2.5 TB isn't very much in a month, especially not for a proxy of a much bigger site. Vultr's bandwidth is notoriously tight for the price, too. I feel like this is the wrong service for that type of host.
Vultr wants me to complete a captcha just to view their website, which tells me an awful lot about them already.
Cloud pricing for bandwidth is really limiting for a lot of applications. For comparison you can get a 1gbit/s line with your server on OVH EU for about $100/mo, which you could utilize for a theoretical ~321TiB/mo total transferred
It's a lot more than my little personal server usually uses in a month though.
It's sure a cost for someone used to working with aws though.